In general, it is known that in a cell, physical property values exhibiting electrical characteristics such as an electric conductivity, an electric permittivity, and a dielectric constant change depending on kinds, statuses or the like of the cell. For example, a muscle cell and a nerve cell show high values of electric conductivities (hereinafter referred to as a cell cytoplasm conductivities) of an extracellular fluid and an intracellular fluid as compared with the case of a skin cell containing therein less water. In addition, when the electric permittivity of the cell is measured by sweeping a frequency, dielectric relaxation characteristics change depending on forms of the cell. Thus, by utilizing such characteristics, qualitative and quantitative analyses, and identification of the cell, and moreover confirmation of presence or absence of a disease, and the like become possible. Also, heretofore, a technique for utilizing a difference in dielectric characteristics between the cells has also been proposed as an identification method in separating the cells or the like from each other by a flow cytometry (for example, refer to Parent Documents 1 and 2).
On the other hand, since the cell causes interfere polarization (Maxwell-Wagner polarization) under an electric field, when a dielectric spectroscopy measurement is carried out with respect to a solution containing therein cells, a frequency dispersion of a complex electric permittivity is obtained. Also, when a relaxation expression such as a Maxwell-Wagner equation is applied to the resulting dielectric spectrum, physical property values exhibiting the electrical characteristics, of the cell, such as a cell cytoplasm electric conductivity κi and a membrane capacitance Cm are obtained. The electrical characteristics of the cell such as a blood cell are measured by utilizing the dielectric spectroscopy in such a manner, thereby making it possible to know the state of the cell in a nondisruptive manner.    Patent Document 1: Publication of the Translation of JP-T-2003-507739    Patent Document 2: Publication of the Translation of JP-T-2005-512042